incomparable

Incomparable Diamond

In 1970, Louis Glick acquired the 890 carat (178 g) rough (407.48 cut) Incomparable Diamond, at that time the world's fourth largest rough diamond. The principal 407-carat stone remains the third largest gem-quality faceted diamond in the world.

Alternate sources claim that this stone was only discovered in the early 1980s in the town of Mbuji Mayi in the Democratic Republic of Congo, by a young girl playing outside her uncle's house, where rubble from a nearby diamond mine had been dumped.

The stone was cut by a team led by Marvin Samuels, who co-owned the stone along with Donald Zale of Zales Jewellers and Louis Glick. In November 1984 the finished stones were put on display: a single golden diamond of 407.48 carats (81.496 g) in a 'triolette' shape, and fourteen additional gems. Notably, the satellite stones cut from the Incomparable varied greatly in colour, from near-colourless to rich yellow-brown.

The largest of these stones still bears the name 'Incomparable Diamond', and was graded by the GIA as internally flawless in 1988.

Unusually, the Incomparable Diamond made an appearance on eBay in November 2002, though it remained unsold with a reserve of £15 million pounds sterling. The auction itself was quizically vague and showed a poor-quality photo.